Current storage management systems employ a number of different methods to perform storage operations on electronic data. For example, data can be stored in primary storage as a primary copy that includes production data, or in secondary storage as various types of secondary copies including, as a backup copy, a snapshot copy, a hierarchical storage management copy (“HSM”), as an archive copy, and as other types of copies.
A primary copy of data is generally a production copy or other “live” version of the data which is used by a software application and is generally in the native format of that application. Primary copy data may be maintained in a local memory or other high-speed storage device that allows for relatively fast data access if necessary. Such primary copy data is typically intended for short term retention (e.g., several hours or days) before some or all of the data is stored as one or more secondary copies, for example to prevent loss of data in the event a problem occurred with the data stored in primary storage.
Secondary copies include point-in-time data and are typically for intended for long-term retention (e.g., weeks, months or years depending on retention criteria, for example as specified in a storage policy as further described herein) before some or all of the data is moved to other storage or discarded. Secondary copies may be indexed so users can browse, search and restore the data at another point in time. After certain primary copy data is backed up, a pointer or other location indicia such as a stub may be placed in the primary copy to indicate the current location of that data. Further details may be found in the assignee's U.S. Pat. No. 7,107,298, filed Sep. 30, 2002, entitled SYSTEM AND METHOD FOR ARCHIVING OBJECTS IN AN INFORMATION STORE (U.S. patent application Ser. No. 10/260,209).
One type of secondary copy is a backup copy. A backup copy is generally a point-in-time copy of the primary copy data stored in a backup format as opposed to in native application format. For example, a backup copy may be stored in a backup format that is optimized for compression and efficient long-term storage. Backup copies generally have relatively long retention periods and may be stored on media with slower retrieval times than other types of secondary copies and media. In some cases, backup copies may be stored at on offsite location.
Another form of secondary copy is a snapshot copy. From an end-user viewpoint, a snapshot may be thought as an instant image of the primary copy data at a given point in time. A snapshot may capture the directory structure of a primary copy volume at a particular moment in time, and may also preserve file attributes and contents. In some embodiments, a snapshot may exist as a virtual file system, parallel to the actual file system. Users may gain a read-only access to the record of files and directories of the snapshot. By electing to restore primary copy data from a snapshot taken at a given point in time, users may also return the current file system to the prior state of the file system that existed when the snapshot was taken.
A snapshot may be created nearly instantly, using a minimum of file space, but may still function as a conventional file system backup. A snapshot may not actually create another physical copy of all the data, but may simply create pointers that are able to map files and directories to specific disk blocks.
In some embodiments, once a snapshot has been taken, subsequent changes to the file system typically do not overwrite the blocks in use at the time of snapshot. Therefore, the initial snapshot may use only a small amount of disk space to record a mapping or other data structure representing or otherwise tracking the blocks that correspond to the current state of the file system. Additional disk space is usually only required when files and directories are actually modified later. Furthermore, when files are modified, typically only the pointers which map to blocks are copied, not the blocks themselves. In some embodiments, for example in the case of copy-on-write snapshots, when a block changes in primary storage, the block is copied to secondary storage before the block is overwritten in primary storage and the snapshot mapping of file system data is updated to reflect the changed block(s) at that particular point in time.
An HSM copy is generally a copy of the primary copy data, but typically includes only a subset of the primary copy data that meets a certain criteria and is usually stored in a format other than the native application format. For example, an HSM copy might include only that data from the primary copy that is larger than a given size threshold or older than a given age threshold and that is stored in a backup format. Often, HSM data is removed from the primary copy, and a stub is stored in the primary copy to indicate its new location. When a user requests access to the HSM data that has been removed or migrated, systems use the stub to locate the data and often make recovery of the data appear transparent even though the HSM data may be stored at a location different from the remaining primary copy data.
An archive copy is generally similar to an HSM copy, however, the data satisfying criteria for removal from the primary copy is generally completely removed with no stub left in the primary copy to indicate the new location (i.e., where it has been moved to). Archive copies of data are generally stored in a backup format or other non-native application format. In addition, archive copies are generally retained for very long periods of time (e.g., years) and in some cases are never deleted. Such archive copies may be made and kept for extended periods in order to meet compliance regulations or for other permanent storage applications.
In some embodiments of storage management systems, application data over its lifetime moves from more expensive quick access storage to less expensive slower access storage. This process of moving data through these various tiers of storage is sometimes referred to as information lifecycle management (“ILM”). This is the process by which data is “aged” from more forms of secondary storage with faster access/restore times down through less expensive secondary storage with slower access/restore times, for example, as the data becomes less important or mission critical over time.
In some embodiments, storage management systems may perform additional operations upon copies, including deduplication, content indexing, data classification, data mining or searching, electronic discovery (E-discovery) management, collaborative searching, encryption and compression.
One example of a system that performs storage operations on electronic data that produce such copies is the Simpana storage management system by CommVault Systems of Oceanport, N.J. The Simpana system leverages a modular storage management architecture that may include, among other things, storage manager components, client or data agent components, and media agent components as further described in U.S. Pat. No. 7,246,207, filed Apr. 5, 2004, entitled SYSTEM AND METHOD FOR DYNAMICALLY PERFORMING STORAGE OPERATIONS IN A COMPUTER NETWORK. The Simpana system also may be hierarchically configured into backup cells to store and retrieve backup copies of electronic data as further described in U.S. Pat. No. 7,395,282, filed Jul. 15, 1999, entitled HIERARCHICAL BACKUP AND RETRIEVAL SYSTEM.
Components within conventional storage management systems often communicate via one or more proprietary network protocols; this limits the devices that may connect to the system. Conventional systems may utilize propriety or non-proprietary network protocols at any of the seven Open Systems Interconnection Reference Model (OSIRM) layers, and may often utilize proprietary application-layer protocols. For example, if a client has primary data stored on it, and a storage management system is utilized to create a secondary copy of this data on a secondary storage device, the client may communicate with the secondary storage device by utilizing a proprietary application-level network protocol. In order to create a secondary copy on the secondary storage device in such a scenario, both the client and secondary storage device must have proprietary software and/or hardware installed or otherwise be configured to perform the proprietary network protocol. Thus, the ability of a conventional storage management system is generally limited to performing storage operations on those clients and secondary storage devices having pre-installed hardware or software.
Although some conventional data storage systems may permit a client to communicate with the system via a non-proprietary network protocol such as hypertext transfer protocol (HTTP) or file transfer protocol (FTP), generally such systems do not facilitate a wide range of value-added storage operations. For example, cloud storage sites typically provide only storage of and access to data objects as a service provided to end users. Generally, uploading, access and manipulation of data stored on a cloud storage site is conducted via an HTTP, FTP or similar network connection. Cloud storage service providers include Amazon Simple Storage Service, Rackspace, Windows Azure, and Iron Mountain, and Nirvanix Storage Delivery Network. Cloud storage service providers often bill end users on a utility computing basis, e.g., per gigabyte stored, uploaded and/or downloaded per month. Conventional cloud storage sites may not permit the end user to perform value-added storage operations such as ILM, deduplication, content indexing, data classification, data mining or searching, E-discovery management, collaborative searching, encryption or compression.
The need exists for systems and methods that overcome the above problems, as well as systems and methods that provide additional benefits. Overall, the examples herein of some prior or related systems and methods and their associated limitations are intended to be illustrative and not exclusive. Other limitations of existing or prior systems and methods will become apparent to those of skill in the art upon reading the following Detailed Description.